This invention relates to a detachable display, in particular to a detachable liquid crystal display for an electronic device.
Liquid crystal displays normally have X address lines and Y address lines, the X address lines and the Y address lines residing on either side of a layer of liquid crystal material. The X address lines and the Y address lines are normally orthogonal to one another so that when a voltage is applied between an X address line and a Y address line, an electric field is produced in the vicinity of the point where the X address line and the Y address line overlap, thereby causing a change in the optical properties of the liquid crystal material in this vicinity.
An electrical contact to an address line is normally made by a wire soldered to the end of the address line. Electrical contacts to the X address lines are made at one edges of the display, and electrical contacts to the Y address lines are made at another edge of the display, the two edges being orthogonal to one another.
The wires can then be electrically connected to one end of a lead, the other end of the lead having a plug attached thereto so that the display can be electrically connected to an electronic device having a socket for receiving the plug. The display can then be detached from the electronic device by removing the plug from the socket. However, such an arrangement is not always convenient.
It is one object of the present invention to address these issues.
According to one aspect of the present invention, there is provided a display comprising: a display panel with a display area and around the display area, a plurality of sides and a connecting edge along one side thereof for detachably connecting the display to a matching electrical connector; a plurality of X address lines extending across the display panel in one direction, each X address line having an X contact; and a plurality of Y address lines extending across the display panel in another direction, each Y address line having a Y contact, wherein the X contacts and the Y contacts lie along the connecting edge.
Because the X contacts and the Y contacts lie along the connecting edge, the display can be connected to and removed from the electrical connector easily, allowing a display connected to the connector to be easily interchanged with another display.
Preferably, each X address line has an addressing portion for addressing a portion of the display area, and a connecting portion for making an electrical connection between an X contact and a corresponding X addressing portion, wherein each of the addressing portions of the X address lines extends in the direction of the connecting edge, and each of the connecting portions of the X address lines extends at an acute angle relative to the direction of the connecting edge, between the corresponding X contact and addressing portion. This will allow a connection between the X contact and the address portion of X address line to be made more simply and more reliably.
Each Y address line will preferably have an addressing portion for addressing a portion of the display area, and a connecting portion for making an electrical connection between a Y contact and a corresponding Y addressing portion, wherein each of the addressing portions of the Y address lines extends in a direction transverse to the direction of the connecting edge, and each of the connecting portions of the Y address lines extends transverse to the direction of the connecting edge between the corresponding addressing portion and Y contact. Because the Y addressing portions extend in a direction transverse to the direction of the connecting edge, each of the Y addressing portions will cross the X address addressing portions, allowing an electric field to be applied at the points where each Y addressing portion crosses an X addressing portion.
The display may have a first face, and parallel to the first face a second face, the display area extending across the first face and/or the second face, wherein the X contacts are accessible from the first face and the Y contacts are accessible from the second face. This will allow the display to be connected to a connector of the slot-type, the connector having two displaced parallel surfaces, one parallel surface having thereon a plurality of X connector pads, and the other surface having thereon a plurality of Y connector pads. The connector pads may have the form of pins or brushes, resilient or rigid, and may have connecting members shaped so as to receive or be received by a corresponding X or Y contact.
The X contacts and/or the Y contacts may each have a contact region, the contact region of each X contact residing in a first plane, and the contact region of each Y contact residing in a second plane displaced and parallel to the first plane. The contact region of each X and/or Y contacts may be substantially flat.
The display will preferably have a first plate and a second plate with an optical medium therebetween, the optical medium being addressable by the X and Y address lines, the X address lines being provided on the first plate and the Y address lines being provided on the second plate. The first and/or second plate will preferably be transparent, so that the optical medium can be viewed.
In order to reduce the risk of the X addressing portions becoming shorted together, either by the connecting portions or otherwise, the addressing portions of the X address lines will preferably be strips of conducting material deposited on an inwardly facing surface of the first plate and the connecting portions of the X address lines will preferably be strips of conducting material deposited on an outwardly facing surface of the first plate. Such an arrangement will reduce the need for an additional insulating layer to be deposited on the first plate between the addressing portions and the connecting portions of the X address lines.
So that connecting windows do not need to be formed through the first plate, the connecting portions of the X address lines will preferably be connected to the addressing portion of the X address lines at an edge of the first plate, not being the connecting edge.
In a preferred embodiment, the display panel will be substantially square or substantially rectangular and the Y address lines and the X address lines will be perpendicular to one another.
In order for the display to electrically connect to the connector in one orientation only, the X contacts and the Y contacts may each be placed along the connecting edge at regular intervals, the intervals between the X contacts being different from the intervals between the Y contacts. Hence if the display is inadvertently inserted into the connector the wrong face up, the X contacts and Y contacts will not line up with the respective X and Y connector pads on the connector.
The display may be flexible so that it can be handled like a sheet of paper when it is removed from the connector.
The optical medium may be a liquid crystal medium. The liquid crystal medium may be bistable, such that the display area holds an image following addressing of the display. An image can then be written over the display area by addressing the X and Y address lines, and the display can then be removed from the connector and stored, in a similar way to conventional paper.
According to another aspect of the invention, there is provided a display assembly comprising an electrical connector and a display, wherein the display has:
a display panel with a display area, and around the display area a plurality of sides and a connecting edge along one side thereof for detachably connecting the display to the electrical connector;
a plurality of X address lines extending across the display panel in one direction, each X address line having an X contact; and,
a plurality of Y address lines extending across the display panel in another direction, each Y address line having a Y contact, wherein the X contacts and the Y contacts lie along the connecting edge,
and wherein the electrical connector is capable of receiving the connecting edge of the display, the electrical connector having a plurality of X connector pads for contacting the X contacts, and a plurality of Y connector pads for contacting the Y contacts, such that when the connector edge of the display is received in the electrical connector, some or all of connector pads connect to the contacts on the display.
Preferably, at least the X contacts will each be placed along the connecting edge of the display at regular intervals, and at least the X connector pads will each be placed at regular intervals on the electrical connector, the size of the intervals between the X connector pads being equal to at most half the size of the interval between the X contacts, and a sensing circuit will preferably be provided for sensing which X connector pads on the connector are connected to the X contacts on the display.
Because the size of the intervals between the X connector pads are equal to at most half of the size of the intervals between the X contacts, the display does not need to be aligned along the direction of the connecting edge in order for each of the X contacts to connect to at least one X connector pad. This will be particularly important, since typically the connecting edge will have about 50 X contacts or more per cm.
The connector assembly may be connected to a computer device, in which case the sensing circuit may be provided within the computer device.
The connecting edge need not be part of a display, and may be part of a plug, the X and/or Y contacts being connected to wires leading to an electronic device. Therefore, according to yet another aspect of the invention, there is provided a connector system comprising a plug and an electrical connector, the plug and the electrical connector being capable of releasably engaging with one another, wherein:
the plug has a connecting edge and a plurality of contacts located along the connecting edge at regular intervals, and the electrical connector has a plurality of connector pads for contacting the contacts, the connector pads being arranged at regular intervals;
the size of the intervals between the connector pads is at most half of the size of the intervals between the contacts, such that when the connector edge of the first plug is received in the electrical connector, each contact connects to at least one connector pads; and
a sensing circuit is provided for sensing which connector pads on the connector are connected to the contacts on the plug.